third_party/WebKit/Source/core/dom/NthIndexCache.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef NthIndexCache_h
   6 #define NthIndexCache_h
   7
   8 #include "core/CoreExport.h"
   9 #include "core/dom/Element.h"
  10 #include "platform/heap/Handle.h"
  11 #include "wtf/HashMap.h"
  12 #include "wtf/OwnPtr.h"
  13 #include "wtf/RefPtr.h"
  14
  15 namespace blink {
  16
  17 class Document;
  18
  19 class CORE_EXPORT NthIndexData final : public NoBaseWillBeGarbageCollected<NthIndexData> {
  20     WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED(NthIndexData);
  21     WTF_MAKE_NONCOPYABLE(NthIndexData);
  22     DECLARE_EMPTY_DESTRUCTOR_WILL_BE_REMOVED(NthIndexData);
  23 public:
  24     NthIndexData() { }
  25
  26     unsigned nthIndex(Element&);
  27     unsigned nthIndexOfType(Element&, const QualifiedName&);
  28     unsigned nthLastIndex(Element&);
  29     unsigned nthLastIndexOfType(Element&, const QualifiedName&);
  30
  31 private:
  32     unsigned cacheNthIndices(Element&);
  33     unsigned cacheNthIndicesOfType(Element&, const QualifiedName&);
  34
  35     WillBeHeapHashMap<RawPtrWillBeMember<Element>, unsigned> m_elementIndexMap;
  36     unsigned m_count = 0;
  37
  38     DECLARE_TRACE();
  39 };
  40
  41 class CORE_EXPORT NthIndexCache final {
  42     STACK_ALLOCATED();
  43     WTF_MAKE_NONCOPYABLE(NthIndexCache);
  44 public:
  45     explicit NthIndexCache(Document&);
  46     ~NthIndexCache();
  47
  48     unsigned nthChildIndex(Element& element)
  49     {
  50         ASSERT(element.parentNode());
  51         return ensureNthIndexDataFor(*element.parentNode()).nthIndex(element);
  52     }
  53
  54     unsigned nthChildIndexOfType(Element& element, const QualifiedName& type)
  55     {
  56         ASSERT(element.parentNode());
  57         return nthIndexDataWithTagName(element).nthIndexOfType(element, type);
  58     }
  59
  60     unsigned nthLastChildIndex(Element& element)
  61     {
  62         ASSERT(element.parentNode());
  63         return ensureNthIndexDataFor(*element.parentNode()).nthLastIndex(element);
  64     }
  65
  66     unsigned nthLastChildIndexOfType(Element& element, const QualifiedName& type)
  67     {
  68         ASSERT(element.parentNode());
  69         return nthIndexDataWithTagName(element).nthLastIndexOfType(element, type);
  70     }
  71
  72 private:
  73     using IndexByType = WillBeHeapHashMap<String, OwnPtrWillBeMember<NthIndexData>>;
  74     using ParentMap = WillBeHeapHashMap<RefPtrWillBeMember<Node>, OwnPtrWillBeMember<NthIndexData>>;
  75     using ParentMapForType = WillBeHeapHashMap<RefPtrWillBeMember<Node>, OwnPtrWillBeMember<IndexByType>>;
  76
  77     NthIndexData& ensureNthIndexDataFor(Node&);
  78     IndexByType& ensureTypeIndexMap(Node&);
  79     NthIndexData& nthIndexDataWithTagName(Element&);
  80
  81     RawPtrWillBeMember<Document> m_document;
  82     OwnPtrWillBeMember<ParentMap> m_parentMap;
  83     OwnPtrWillBeMember<ParentMapForType> m_parentMapForType;
  84
  85 #if ENABLE(ASSERT)
  86     uint64_t m_domTreeVersion;
  87 #endif
  88 };
  89
  90 } // namespace blink
  91
  92 #endif // NthIndexCache_h